Just two years after arriving in Washington, Senator Barack Obama of Illinois made it clear to the American public on Tuesday that he fully intends to enter the Democratic presidential race, creating an exploratory committee while preparing to open a full-fledged campaign next month to become the nation’s first African-American president. The announcement by Senator Obama removed any doubt about his candidacy and ended weeks of speculation, fueled in part by the senator himself, that sent ripples through the ranks of other Democrats eyeing the presidential nomination. He said that he will formally declare his intention to run on February 10th in Springfield, Ill., the home of Abraham Lincoln.

“Our leaders in Washington seem incapable of working together in a practical, common-sense way,” Mr. Obama said, speaking in a video address sent to his supporters. “Politics has become so bitter and partisan, so gummed up by money and influence, that we can’t tackle the big problems that demand solutions.” His announcement emphasized the point that he, as opposed to other Democratic candidates, will be the fresh, unifying face of the party.